Most web applications are built by teams of software developers and graphic designers. When software developers build their own sites, they tend to reuse designs they’ve used before or borrow from sites they like. Sometimes they’ll ask a graphic designer to create a few icons or propose a fresh look and feel. For their part, graphic designers tend to want to create the kind of eye-catching design that will win design awards for innovation and creativity. In my experience, most developers and designers are only dimly aware that there is a profession called “Interaction Design.” With any profession, there is a body of knowledge and expertise, and in Interaction Design, it’s all devoted to developing the optimal user experience. Most web applications need interaction design. At a minimum, developers and designers would do well to familiarize themselves with the accumulated body of knowledge from the interaction design field. And, if possible, get an interaction design expert on your team.